(Reuters) - Bayern Munich midfielder Thiago Alcantara is set for a lengthy spell on the sidelines after sustaining a thigh injury during Wednesday's 2-1 Champions League win over RSC Anderlecht, the German champions said on Thursday.

Spain international Thiago was substituted prior to halftime before Robert Lewandowski and Corentin Tolisso scored in the second half to extend Bayern's winning run to nine matches across all competitions under manager Jupp Heynckes.

"Bayern are set to be without midfielder Thiago for a lengthy period of time," Bayern said on their website. (fcbayern.com)

"Coach Jupp Heynckes revealed that the Spain international 'most probably has a serious muscle injury in his thigh'."

Bayern sealed qualification to the Champions League knockout stages last month and host Group B leaders Paris St Germain in their final group game on Dec. 5.